8668558991 has 4 divisors (see below), whose sum is σ = 8673633000. Its totient is φ = 8663484984.

The previous prime is 8668558981. The next prime is 8668559027. The reversal of 8668558991 is 1998558668.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8668558991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8668558981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2534441 + ... + 2537858.

It is an arithmetic number, because the mean of its divisors is an integer number (2168408250).

Almost surely, 2^8668558991 is an apocalyptic number.

8668558991 is a deficient number, since it is larger than the sum of its proper divisors (5074009).

8668558991 is a wasteful number, since it uses less digits than its factorization.

8668558991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5074008.

The product of its digits is 37324800, while the sum is 65.

The square root of 8668558991 is about 93105.0964824160. The cubic root of 8668558991 is about 2054.2295378186.

The spelling of 8668558991 in words is "eight billion, six hundred sixty-eight million, five hundred fifty-eight thousand, nine hundred ninety-one".